SAN’s solution or not

I have a budget of ?40,000 ($80,000) and am looking for a good data storage solution. At the moment I am using a server with 300GB storage running with raid 5 and a legato backup solution. I am starting to reach capacity on the existing solution so am considering my options. What do I move to ? is there anyone that has experience of SAN?s – what do you recommend..

Thanks